Here's The Optimal Length For A Tweet If You Want That Tweet To Be Retweeted

It's not obvious that the length of a tweet on Twitter
might affect the number of people who engage with it. After all,
tweets are all roughly the same length: Fewer than 140
characters.

But advertisers who use Twitter to reach their consumer fans --
especially those who are paying for promoted tweets -- need every
degree of leverage they can get. Social media marketing and
analytics company Track Social decided to measure whether tweet
length affected the likelihood of getting a retweet from others
on Twitter. The company found that the sweet spot for tweet
length is 71-100 characters:

Track Social

Bonus points: If you noticed that the headline on this article --
which tweets automatically from BI's accounts -- was written to
hit the retweet sweet spot. It's 76 characters long.